By a vote of 69-27, the Senate passed a bill on Monday that would require online retailers to collect and distribute sales taxes according to the tax laws of the fifty states.

Under current law, retailers are only required to collect sales taxes for online purchases originating in states where they have a physical presence. The Senate's bill is supported by national brick-and-mortar chains and Amazon, both of whom would gain a competitive advantage by the increased burden the bill would place on small and mid-size retailers that sell online (the bill exempts businesses with less than $1 million in annual sales). Opposition to the bill is being led by eBay, which has organized a coalition of small online retailers and activated its sellers to lobby Congress on the bill.

Data: MapLight analysis of campaign contributions from interest groups that have taken a position on S. 743 (Marketplace Fairness Act) to members of the Senate from January 1, 2007—December 31, 2012. Contributions data source: Center for Responsive Politics

Amazon contributions to the Senate total $208,428.

eBay contributions to the Senate total $177,900.

Interest groups supporting the bill (including Amazon, Walmart, AFL-CIO) have given 40 times as much money to senators than interest groups opposing (including eBay, TechNet, FreedomWorks).

Senators voting "YES" received, on average, 53% more money from Amazon than from eBay.

Senators voting "YES" received 29% more money, on average, from interest groups supporting the bill than senators voting "NO."

Methodology: MapLight analysis of campaign contributions from interest groups that have taken a position on S. 743 to current members of the Senate, from January 1, 2007—December 31, 2012. Contributions data source: OpenSecrets.org

About MapLight: MapLight is a 501(c)(3) nonprofit, nonpartisan research organization that reveals money's influence on politics. If our work has been helpful to you, please consider supporting us.

About our data

Read the details about our data sources and methodology. Data refers to direct contributions to the campaign committees of elected legislators. For example, contribution totals exclude contributions to party committees such as the RNC or the DNC and exclude contributions made to individuals that did not win their election.

For U.S. Congress, contributions data provided by the Center for Responsive Politics (OpenSecrets.org) and legislative data provided by GovTrack.us.

California contributions data provided by the National Institute on Money in State Politics (FollowTheMoney.org).